SYNTHESES, CHARACTERIZATION AND LIQUID CRYSTALLINE PROPERTIES OF NEW BIS[5-((4-ⁿALKOXYPHENYLAZO)-N-(ⁿALKYL)-SALICYLALDIMINATO] COPPER(II) AND NICKEL(II) COMPLEX HOMOLOGUES

Zolfaghar Rezvani,^a* Leili Rahimi Ahar,^a Kamellia Nejati,^b and Seyed Masoud Seyedahmadian^a
a Department of Chemistry, Faculty of Science, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran. Fax & Tel: +98 412 4524991, E-mail: z_rezvani@yahoo.com.
^b Department of Chemistry, Payam Noor University-Tabriz Center, Emamieh ,Hakim Nezami Street, Tabriz, Iran.

Abstract
A series of bidentate Schiff base ligands, 5-((4- ⁿalkoxyphenyl)azo)-N-(ⁿalkyl)-salicylal- dimine (ⁿalkoxy = octyloxy, dodecyloxy, ⁿalkyl=Butyl, ⁿhexyl) homologues, have been synthesized and characterized by IR, NMR, mass spectroscopy and elemental analyses. For all the ligands the nickel(II) and copper (II) complexes have been synthesized and characterized by elemental analyses and IR spectroscopy. The mesomorphic character of these compounds was studied by using differential scanning calorimetry (DSC) and polarizing microscope equipped with a heating and cooling stage. None of the Schiff-base ligands exhibit liquid crystalline properties but some of the copper complexes show a nematic mesophase.

Key words: Schiff bases, salicylaldimine, metallomesogen, nematic, copper complexes